Sahoo Chittaranjan, Gupta Ashok K
a Environmental Engineering Division , Department of Civil Engineering , Indian Institute of Technology , Kharagpur , India.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2015;50(7):659-68. doi: 10.1080/10934529.2015.1011958.
Commercially available microcrystalline TiO2 was doped with silver, ferrous and ferric ion (1.0 mol %) using silver nitrate, ferrous sulfate and ferric nitrate solutions following the liquid impregnation technology. The catalysts prepared were characterised by FESEM, XRD, FTIR, DRS, particle size and micropore analysis. The photocatalytic activity of the prepared catalysts was tested on the degradation of two model dyes, methylene blue (3,7-bis (Dimethylamino)-phenothiazin-5-ium chloride, a cationic thiazine dye) and methyl blue (disodium;4-[4-[[4-(4-sulfonatoanilino)phenyl]-[4-(4-sulfonatophenyl)azaniumylidenecyclohexa-2,5-dien-1-ylidene]methyl]anilino]benzene sulfonate, an anionic triphenyl methane dye) under irradiation by UV and visible light in a batch reactor. The efficiency of the photocatalysts under UV and visible light was compared to ascertain the light range for effective utilization. The catalysts were found to have the anatase crystalline structure and their particle size is in a range of 140-250 nm. In the case of Fe(2+) doped TiO2 and Fe(3+) doped TiO2, there was a greater shift in the optical absorption towards the visible range. Under UV light, Ag(+) doped TiO2 was the most efficient catalyst and the corresponding decolorization was more than 99% for both the dyes. Under visible light, Fe(3+) doped TiO2 was the most efficient photocatalyst with more than 96% and 90% decolorization for methylene blue and methyl blue, respectively. The kinetics of the reaction under both UV and visible light was investigated using the Langmuir-Hinshelwood pseudo-first-order kinetic model. Kinetic measurements confirmed that, Ag(+) doped TiO2 was most efficient in the UV range, while Fe(3+) doped TiO2 was most efficient in the visible range.
采用液相浸渍技术，使用硝酸银、硫酸亚铁和硝酸铁溶液，将市售微晶二氧化钛掺杂银、亚铁离子和铁离子（1.0摩尔%）。通过场发射扫描电子显微镜（FESEM）、X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、漫反射光谱（DRS）、粒度和微孔分析对制备的催化剂进行表征。在间歇式反应器中，以两种模型染料亚甲基蓝（3,7-双（二甲基氨基）-吩噻嗪-5-鎓氯化物，一种阳离子噻嗪染料）和甲基蓝（二钠盐；4-[4-[[4-（4-磺基苯胺基）苯基]-[4-（4-磺基苯基）氮鎓亚基环己-2,5-二烯-1-亚基]甲基]苯胺基]苯磺酸盐，一种阴离子三苯甲烷染料）的降解为对象，测试制备催化剂的光催化活性。比较光催化剂在紫外光和可见光下的效率，以确定有效利用的光范围。发现催化剂具有锐钛矿晶体结构，其粒径在140-250nm范围内。在Fe(2+)掺杂的TiO2和Fe(3+)掺杂的TiO2的情况下，光吸收向可见光范围有更大的偏移。在紫外光下，Ag(+)掺杂的TiO2是最有效的催化剂，两种染料的相应脱色率均超过99%。在可见光下，Fe(3+)掺杂的TiO2是最有效的光催化剂，亚甲基蓝和甲基蓝的脱色率分别超过96%和90%。使用朗缪尔-欣谢尔伍德准一级动力学模型研究了紫外光和可见光下的反应动力学。动力学测量证实，Ag(+)掺杂的TiO2在紫外光范围内最有效，而Fe(3+)掺杂的TiO2在可见光范围内最有效。
